643180956 has 24 divisors (see below), whose sum is σ = 1637188224. Its totient is φ = 194903280.

The previous prime is 643180933. The next prime is 643180969. The reversal of 643180956 is 659081346.

It is a super-2 number, since 2×643180956² = 827363484322147872, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2436160 + ... + 2436423.

It is an arithmetic number, because the mean of its divisors is an integer number (68216176).

Almost surely, 2^643180956 is an apocalyptic number.

643180956 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

643180956 is an abundant number, since it is smaller than the sum of its proper divisors (994007268).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643180956 is a wasteful number, since it uses less digits than its factorization.

643180956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4872601 (or 4872599 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 643180956 is about 25361.0125192193. The cubic root of 643180956 is about 863.1992591877.

The spelling of 643180956 in words is "six hundred forty-three million, one hundred eighty thousand, nine hundred fifty-six".